Calipers.



No. 672,493. Patented Apr. 23, I90! E. RAUS.

CALIPERS.

(Application filed Nov. 10, 1900.)

TI G. 1.

(No Model.)

)0 a ERASMUfi mus.

BY4V-V-YMA1AT'LTY lTED STATES arnwr Unmet.

ERASMUS RAUS, OF CLEVELAND, OHIO.

CALIPERS'.

SPECIFICATION forming part of Letters Patent No. 672,493, dated April 23, 1901.

Application filed November 10, 1900. Serial No. 36031. (No model .have invented certain new and useful Improvements in Calipers; and I do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to calipers; and the object of the invention is to provide an instrument for taking the exact diameter of internally-threaded objects of whatever kind as, for example, the diameter of a nut, as shown in the accompanying drawings, the diameter of a threaded pipe, tube, or other article.

To these ends the invention consists in the construction, combination, and arrangement of parts,substantially as shown and described, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a plain elevation of my new style of calipers and a cross-section of a nut to show their use. Fig. 2 is an edge elevation of r the calipers alone, and Fig. 3 is a perspective view of the adjusting-bracket designed to set the device at any desired adjustment.

The instrument thus shown comprises, first of all, two similar and equal side bars A and B, having teeth 3 and 4: at their respective ends on their outer edges, the said ends being each offset inward at their extremities, substantially as shown, to enable the smallest diameters possible to be measured and at the same time afford room between said bars for theconnectingandoperatingparts. Theplan on which the device is constructed and operates contemplates the connection of bars A and B in parallel lines laterally adjustable in respect to each other and also lengthwise adjustable one to the other at least the full measure of the pitch of the screw to be gaged and as will hereinafter more fully appear. To these several ends an arm 0 is affixed rigidly to bar A and extends across bar B and beyond the same some distance, so as to accommodate the widest possible lateral adj ustment of said bars, substantially as shown in dotted linesin Fig. 1. Two sets of toggle-links 5 and 6, respectively, connect side barsA and B and are connected at theirinner ends with the ends of connecting-bar D. Said barD is parallel to and centrally between side bars A and B and is the immediate member through which the links 5 and 6 are controlled and held rigidly at any adjustment. To this end also I employ a spiral spring 7, wound spirally about bar D and bearing at its ends against collars on said bar. The lower of these collars especially is adapted to slide on bar D, and its constant tension is exerted to spread the device and throw bars A and B apart, so that the device will spread wide open through said spring, if it be not held orlocked. Then also to operate it the side bars are gripped between the fingers and pressed toward each other against the tension of the spring and in taking measurements are locked when the desired measurement has been made. Now to effect this locking I employ in this instance a bracket E, Fig. 3, constructed at 10 to slide on arm 0 and provided with a set-nut 12 to fasten it. By this means an approximate measurement may be made without special care. Then to get the finer measurement and to fix the device thereat l employ a set-nut 13 higher up. This nut also passes through bracket E and bears against the edge of bar B. The counter-pressure on said bar is from spring 7, so that bar B will hold its place when once adjusted by these means; but there is also a third adjustment wanted to measure the pitch of the thread as well, and this is obtained through screw 14 at the top in the right angled extremity of bracket E. This screw bears on a lug or projection 15 on arm B, holding it down, while keeper 16 on said bar, bearing on arm, takes the pressure in that direction. This makes a rigid construction and locks all the said parts together when said several screws are tightened. Of course I regard this rather one of several ways in which these adjustments may be effected, and hence I regard my invention as broad as any and all equivalents of what I here show and describe.

The adjustment for pitch referred to is seen in Fig. 1, where a nut G is shown as the object to be gaged. In this case the device would be spread to the width of the diameter approximately and set by thumb-screw 12. Then the finer adjustment would be by screw 13 and the pitch adjusted or fixed by screw 14:. This done the device would be removed from the nut by simply compressing it in the hand enough to release teeth 3 from. the

5 threads, and then all the parts would resume or go back to the place at which the several nuts fixed them and remain there until the, bolt, tube, pipe, or other article for which the measurements were taken had the size of bore and pitch of thread given thereto, thus matching said part accurately with confidencethat it will fit and work as designed.

If preferred, one set of the teeth 3and4 may be omitted, in which case the side meas:

uring-bars A and B would not extend beyond the links at that end. l

The keeper 16 serves especially to hold bar B and arm 0 closely together and is deep enough lengthwise to allow bar B to be depressed in respect to arm C, as seen in dotted lines, Fig. l.

The offset or shoulder whereby either ex tremities 17 or 18 are-formedis of suchdepth 1 as to enable the link-connecting bar to lie be tween said bars when the extremities at either or both ends are brought against each other. The toggle-links overlap the middle bar, so that they do not fold between the side bars. WhatI claim is o ,f": 1. In cali ers aset of side measurin -bars having teeth at their ends toengage in threads,

;link mechanism connecting said bars con structed and arranged to hold the bars parallel at all times, a ,rigid member on one of 5 said bars, and means on the other bar ad ..justably. connected with said member to provide both a lateral. andvertical adjustment of said bars, substantially as described.

1 2., .In,cali pers,,a set ot side measuring-bars, 40 two sets of linksof equal le ngth, and a central bar uniting the ,said side bars, a crossarm on one of said measuring-bars and a spring about the central bar bearing on said arm, whereby the device is spread apart, sub- .stantially as described.

, 3. The twoside barswith teeth at their ends outside, two sets of links of equal length connecting said bars, a central bar uniting the inner ends of said links, a cross-arm rigid with one of said side bars and slidably engaged with the other side bar, and a spring to spreadthe device, substantially as described.

4. The side bars and the mechanism pivotally connecting them in parallel lines, a transverse arm rigid with one of said bars and slidably connected with the other bar, and means on said arm to adjust said bars in relation tov each other andthework to be measured, substantially as described.

5. A set of thread-measuring bars and means connecting said bars constructed to hold them ihovabl'e parallel relation, a transverse member on one of said bars, and

means adjustably mounted onsaid member to set said bars in parallel relation and'to'allow one bar to belengthwise adjusted in respect to the other bar, substantially as described.

6. Thetw'oside measuring-barsand the l ink conne'ctions for holding them parallel, a trans'verse'arm on one of said bars; a projection and keeper on's'aido'ther bar, and means to engage said arm andprojection to'a'djust and set said bars in distance and lengthwise adj u'stmentr'elation with each other, substantially as described; l

7. The sidebars andthe toggle mechanism connecting them, a cross-arm rigid 'With one of sa'id bars'and having slidabl'e connection with the other bar, a bracket adjustableon said arm outsidethe 'free side bar,'and a'setscrew onsaid bracket to determine thelateral adjustments of said bars,-substantially as described v 8. The device havi'r1g"slide m'ea'su'ring bars "and means to hold them paralleh'atransverse arm connected w'ith saidbars anda bracket adjustable" on said arm and provided with screws to fix said device in all its adjustments, 

